Influence of the membrane environment on vibrational motions in reaction centres of Rhodobacter sphaeroides

A comparison is made between the femtosecond oscillatory kinetics in membranes and in detergent-solubilized reaction centres of the antenna-deficient RCO1 mutant of Rhodobacter sphaeroides. The main features are very similar, both at room temperature and at 10 K, but the dampening of the oscillations occurs somewhat more slowly in membranes. The results indicate that the observed coherent vibrations involve the protein matrix surrounding the chromophores.